Seagull Bucker JU-133 Jungmeister ARF Review
Review by Gunnar Hovmark, Staff Contributor
- Spektrum DX6 transmitter
- Spektrum AR 610 receiver
- E-Flite 90 Power 325 Kv motor
- E-Flite 80 Amp SB Brushless ESC
- 2 x E-Max ES3051 (aileron servos)
- 3 x Futaba S3003 (rudder and right & left elevator servos)
- Gravity 6-cell 5500 mAh battery, weight 860 grams
- APC 22 x 10 E propeller
- 5 mm birch plywood for motor mount
- Y connectors for aileron/elevator servos
- Extension wires for the aileron servos
- Flies great
- Looks really impressive in the air
My plane had a few quality issues. See “Assembly”
A very important part of model aviation is to make an impression on the spectators. If you agree, then you need this plane. You will enjoy flying it. The “A” in ARF has to be taken seriously here, but if you spend a little time to get things right you are richly rewarded.
For this review I have had help from Graeme Brown, who you can find flying his Jungmeister at the Penrith Electric Model Aero Club near Sydney, Australia. Check out their Facebook page, they always have something interesting going on!
This is an ARF model, i.e. almost ready to fly. Everything you need is in the box except the “equipment used” I have listed. The text in the manual is confusing in a few places, but the photos are good, so you'll have no problems using it. A few things should be mentioned though. The manual says you should put the CG at 180 mm from the upper wing's leading edge. However, Graeme has very strongly advised me to put it further forward, at 160 mm from the leading edge. I did that and I believe he's right. Another thing to keep in mind is that the fitting of the motor mount and the cowl is best done with the plane standing on the rear end of the fuselage, with the nose pointing straight up, so be sure you do that before you add the tail surfaces. The lower wings are held in place with nylon screws that go into threaded tubes in the wing roots. Problem: the tube was missing in my right wing root. Fortunately I have a huge collection of exotic screws and nuts in my garage, so I could quickly find two suitable nuts that I could glue into the right wing root with “extra strong” epoxy. Graeme didn't run into the same problem, so hopefully nobody else will either.
The covering needed tightening in a few places. I used an ordinary household iron, but a covering iron is probably better. The glue that's used for the fuselage is not very strong. That's OK most of the time, but there are four things that really need epoxy. That's the servo tray, the former that the tail wheel is bolted to, the plywood parts in the fuselage that hold the nylon screws that keep the lower wings attached, and the firewall. Add a little epoxy there to keep those plywood parts in place. Another little snag that both I and Graeme had to fix: there should be two wing struts out on the right wing and two on the left. However, the box contained four wing struts for the right side and none for the left. To convert the wing struts you have to remove the blind nuts and put them on the other side of the strut, then cover the hole you made to get the nuts out with something black. I used scrap pieces of black Solite.
The manual talks about “the holes” for the screws that hold the landing gear. After an extensive search I concluded that those holes didn't exist, so I had to drill them myself. A bit of care is needed to get them in the right places. My Jungmeister did not come with an electric conversion kit, but I really like electric planes so I decided from the very start to go electric. Also, Graeme had already done it so I knew it could be done. I built the motor mount from 5 mm birch plywood in the shape of a box and fastened it to the firewall with “extra strong” epoxy and four screws. At first I put the battery inside the fuel tank compartment, but that way I couldn't use it to balance the plane and had to put 300 grams of ballast in the nose. Not good, so I took a saw and made a hole in the firewall and moved the battery forward, protruding into the motor mount. That way I could remove all the ballast, much better. My Jungmeister weighs roughly 5.6 kilograms complete with battery. The Jungmeister comes with a large sheet of self-adhesive decals. To decide which of them to use and where to put them it's best to turn to the Internet. There is a huge number of pictures of Jungmeisters on the web, and you can also read about the plane's interesting history. Oh, by the way, don't use the mirror image registration letters with the dashed outline.
My setup of motor, battery and propeller seems very appropriate for this plane. The Jungmeister's nose is big and blunt, so you really need a big propeller to get good thrust. A “scale” propeller size is between 21 and 22 inches judging from the drawings of Jungmeisters I have seen, so it's a good idea to choose a motor that can swing propellers of that size. The Jungmeister is pretty big, it's actually quarter scale, but thanks to the large wing area you can still take off and land in a fairly small space. The Jungmeister's flying qualities will not give you any big surprises. I need to use the rudder to make turns look good. I can make large loops and climb almost vertically. To make really good-looking aerobatic maneuvers with the Jungmeister I need good coordination between my left and right hand. I'm not quite there yet, but when I get things right I'm sure it will look really impressive. The full-scale Jungmeister has been called “The Stradivarius of aerobatic planes”, and with the right pilot I think this model can look the part.
I love it!